


Third Day With The Art Thief

by DanaKeylits



Category: Castle
Genre: Multi, Prompt Fill
Language: English
Status: Completed
Published: 2014-06-06
Updated: 2014-06-06
Packaged: 2018-02-03 14:31:05
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,862
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1747961
Author URL: https://archiveofourown.org/users/DanaKeylits/pseuds/DanaKeylits
Summary: <blockquote class="userstuff">
              <p>Summer Hiatus 14 Kink Meme prompt: Serena's back in town and this time she wants them both.</p>
            </blockquote>





	Third Day With The Art Thief

**Third Day With the Art Thief  
** By Dana Keylits

* * *

 

  **A/N:** _Just a warning, if you follow my work on FFNet, you should know that this is much more graphic than I usually write. In both description and subject matter. If you are looking for an M rated fic, you should NOT read this. It is most certainly NC-17._

_I wrote this for the 2014 Summer Hiatus Kink-Meme at[kinkofthecastle](http://kinkofthecastle.livejournal.com/2713.html?thread=844441#t844441)  
_

* * *

  **S** erena sidled up to them with a cat-like grace, her silky teal robe ‘accidentally’ falling open, partially exposing the swell of her breasts. Kate could tell the art thief knew _exactly_ what she was doing, and she couldn’t take her eyes off the woman, excitement singeing every edge and corner of her body. She could sense Castle behind her, could feel _his_ excitement as he bumped into her, his burgeoning erection colliding with the small of her back, and she reached for him, palming him through his jeans, rewarded by the sudden grunt and whimper that ascended his throat.

His breath was hot on her neck and she smiled, aware of the power she possessed, having been gatekeeper for these particular activities. It hadn’t taken much convincing, her of him, ironically; most would think the other way around. But, it was a bucket list item for her, something she’d long fantasized about, and something Castle was willing to give her. Oh, he _pretended_ to be reticent, but Kate knew this was a fantasy of _his_ as well.

And so, when on the third day of their unlikely _repeat_ alliance investigating yet another art theft turned murder investigation, Serena had suggested it, and Kate had thought, why not?

You only live once.

As Serena floated towards them, the floor-length robe unfastened even wider and Kate caught a glimpse of the downy patch of hair that nestled at the apex of Serena’s thighs. She suddenly felt a twinge of pleasure radiate through her center, and, on any other day that would have confused her, would have alarmed her. But not today, not now, not with Castle hard and panting behind her, Serena inviting, exotic, enticing in front of her. Not after they’d decided they’d try it, a threesome, something that, to Kate’s surprise, not even Castle had done before.

She was wet.

And, wanting.

And, eager to get started.

“Detective,” Serena purred as she reached the pair, one finger slowly tracing her bottom lip. “I’ll admit. I’m a little surprised you accepted my invitation.” She reached out and palmed Kate’s cheek, running the pad of her thumb along the Detectives chin before finally looking at Castle and smiling. “But, I’m glad you did.” She took a step backwards and gestured into the expensive hotel suite, her robe briefly opening wide enough that Kate caught a glimpse of her gumdrop shaped, _erect_ nipple. Another twinge of pleasure coursed through her. “Come. I have wine.” She informed them, turning around to sashay towards the wet bar.

Castle half-growled half-chuckled in Kate’s ear. “Are you sure? Kate. Are you sure we’re doing this? Because, I...”

Kate spun on him, her hand skating over his ample bulge, her thumb stroking its length. “I’m sure, Castle. I want to do this with you.” She seized his mouth, trapping his bottom lip between her teeth and then letting it go, her tongue darting out to sooth his reddened flesh. She searched his baby blue’s. “Do you still..?”

“Yes,” he interrupted eagerly. “Yes, I do.”

She gave him a squeeze. “Good boy,” she praised, using her best dom voice. “ _Very_ good boy.”  

There was that half-growling, half-chuckling thing again and Kate offered him a crooked smile, thoroughly enjoying the crimson effect her teasing was having on his normally pale skin. She slowly turned, deliberately brushing her hip against his straining erection, and followed Serena to the wet bar.

“What’s your poison, Detective?”

“Whatever you’re having,” Kate replied, her voice husky, hushed, seductive. Serena took immediate notice and smiled, uncorking a bottle of Pinot Grigio and pouring it into an oversized wine tumbler. Their fingers briefly touched as Serena handed her the glass, and Kate immediately felt a spark of carnal electricity pass between them.

“Oooh,” Serena whispered, wagging her eyebrow.

She must have felt it, too.

“And, Rick?” Serena asked, looking past Kate to Castle, her eyes flickering to the obvious bulge in his pants. “What can I pour for you?”

Castle cleared his throat but his voice still squeaked when he answered, “I’ll have the same.”

A gentle _pinging_ echoed around them as they clinked glasses, each taking a long sip of the buttery un-oaked wine, their eyes darting from one to the other in erotic anticipation. Finally, Serena took Kate’s hand and led her to the couch, sitting on one end with one leg crossed over the other, one bare foot lazily swinging back and forth, she patting the seat beside her for Kate to sit. “I didn’t peg you for a swinger, Detective Beckett.” She head nodded in Castle’s direction, he was still standing by the wet bar as though rooted to the spot, holding his wine glass in front of his lips, watching the two women with wide eyes and breathless interest. “ _Him_ , I figured. But, you?” she shook her head, her blonde curls bouncing around her face. “Not in a million years.”

Kate took a sip of her wine, her gaze never leaving Serena’s and explained. “I’ve never _swung_ before, Serena.” she licked a remnant of the wine from her lips and blinked. “This will be a _first_.”

One carefully sculpted eyebrow shot up and Serena grinned. “Reaaaaally,” she replied, tucking her chin as she looked at Kate. She leaned forward, capturing an errant strand of chestnut hair between her first and second finger and placing it behind Kate’s ear. “You’re a threesome virgin, are you?”

Kate could feel the blood rushing past her ears, her heart thundering in her chest, and she had to actually _remind_ herself to breathe. She nodded.

Serena closed the space between them and Kate could smell the wine on her breath, feel the warmth of her breath on her cheek. She hovered there, hushed and unmoving, until, her eyes fluttering closed, Kate finally tipped her head and their lips brushed, a gentle press, a whispered meeting.

Kate gasped.

She heard Castle gasp.

And, they kissed.

Just barely, a ghosted, gentle union of their lips, their tongues, but enough that Kate felt like she was on _fire_ , gasping and dizzy, disoriented, as though this were her first time, which, she supposed, it _was_.

Serena leaned back, her eyes blazing, her lips wet and swollen. “Well,” She cocked her head seductively, “...I am going to _thoroughly_ enjoy popping your threesome cherry.”

“I’m a virgin, too!” Castle interrupted, taking a step towards the pair. “I mean, not a virgin, you know, heheh. Not,” he scratched the stubble on his chin. “Not an _actual_ virgin, I’ve had plenty of...” he caught Kate’s disapproving stare and flinched. “...I mean, I’ve been with...“ Kate was still sending lasers. “But, you know, never more than one at a time. So…” he sat down beside Kate on the couch. “…you know. I’m...” he raised his hand as though a schoolboy in class, “...a threesome virgin, too.”

Kate rolled her eyes 

During Castle’s bumbling confession, Serena had placed her hand on Kate’s bare thigh – Kate had worn a periwinkle just-above-the-knee-length dress, with cap sleeves, a V-neck collar, and buttons down the front – which gave Serena easy access to her endlessly long legs. Kate shuddered as Serena’s fingers danced against her flesh.  

_High_ on her thigh.

And, she was quietly inching her way higher. Serena laughed. “Now _that_ _does_ surprise me.”

Castle shrugged, taking a generous swig of his wine as he watched Serena’s hand move higher and higher, and, to his surprise, Kate’s legs move wider and wider apart.

“Detective," 

“Kate, call me Kate.”

“Kate,” Serena corrected. “Have you ever been with a woman before?” she leaned in again, brushing her lips along Kate’s jaw, mapping a path down the column of her throat. 

“Ah, no, yes, well no, not really.” 

Serena pulled away, her curiosity obviously piqued.

“Yes?” Castle asked, his eyebrows hiked as he stared at Kate.

“I mean, I’ve kissed another woman,” she explained, looking from Castle to Serena, then back to Castle. “But, that was about it.”

“ _About_ it?” He asked, crisscrossing lines peppering his forehead.

“More or less,” Kate confessed. She smiled, cocking her head. “Why? Does that turn you on, Castle?”

“Well, yeah,” he confirmed, and then shifting his gaze to Kate’s thigh where Serena’s hand still lay, he added, “Just like _that_ turns me on.”

 Serena set her glass on the table beside the couch and unfolded her legs, leaning closer to Kate. She reached for Castle’s hand. “Then _this_ should _really_ turn you on, Rick.” She led his hand to Kate’s thigh, pushing it higher and higher until his fingertips were grazing Kate’s underwear. A spark flooded through her body as his fingers grazed the soft fabric. “Take them off,” Serena ordered, getting on her knees in front of Kate. She took the Detectives wine glass and placed it on the table beside her own. Kate leaned against the back of the couch, raising her hips off the cushion, her heart racing, her cheeks flushed, her mind swimming with dirty, carnal, _forbidden_ thoughts, with anticipation of what Serena was about to do to her, with her, with _Castle_.

Castle reached beneath her dress with both hands and, his hooded eyes locked on hers, tucked his fingers beneath the waistband of her bikini underwear, easily pulling them down, slowly lowering them past her sun-kissed thighs, over her knees, tickling her calves as they dropped at her stiletto-clad feet. She slid her feet out of them and he picked them up, stuffing them in his jacket pocket, for reasons of which even _he_ didn’t know.

Serena ran both hands along Kate’s thighs, scraping her flesh with well-manicured fingernails, leaving wayward white trails in their wake. Castle gulped his wine as he watched the attractive blonde pull Kate forward, scooting her to the edge of the couch and then gently urging her legs wider, offering a kittenish grin as Castle moaned and gasped beside them.

Kate was so wet, her sex throbbing, hot desire racing through every vein and cell and fiber of her body. Just as Serena ducked her head between Kate’s legs, Kate reached over, palming Castle’s hardened erection. “Ohhh, ahhhh.” She moaned, as Serena’s tongue flicked against her swollen clit, explosions of pleasure rippling from her center to the top of her head and the tips of her toes.

Castle finally set his wine glass down, and then leaned in, hungrily capturing Kate’s mouth with his own, his tongue diving past her lips in an unbridled tango. He tasted sweet like chocolate and strawberries, his breath warm, comforting, familiar. She raked her fingers through his hair, smashing his lips against hers until they finally broke, panting, reckless. Kate bucked her hips and Serena thrust down on her pelvis, trying to get her to hold still. “Gawwwwwd,” Kate cried, closing her eyes, throwing her head back against the sofa cushions as Castle worked his way down the buttons of her dress.

He was kneeling beside her now, his hand slipping beneath the stiff fabric of her bra, his fingers pinching and twisting her nipples as though in perfect cadence to Serena’s tongue, as though they had rehearsed this, or done it before, or _both_. She reached for his belt buckle, fumbling with it before finally demanding, “Off,” when she couldn’t get her wretched fingers to work. He quickly obliged, unzipping, too, and then she reached beneath his boxers, curling her fingers around him and pulling him out.

He groaned as her lips surrounded his tip, her tongue swirling the bead of moisture that had popped up before she took him deeper, sucking harder, her palm caressing his balls. He cradled her head with one hand as she took the length of him into her mouth, her tongue and lips sliding up and down his thick shaft.

Kate relished the headiness of Serena’s feminine lips against her clit while Castle’s swollen cock was in her mouth. She slid him in and out, enjoying his groans and moans and _‘oh fucks’_ , the rise of his breath, and she kept time with Serena, as though she were a human metronome instituting the rhythm of some musical masterpiece. 

And then, abruptly, just as Kate was spiraling higher, Castle, too, Serena stopped. Kate opened her eyes, her lips smacking as she let Castle slide out of her mouth. She turned towards Serena. “Why’d you stop?”

Serena chin nodded at Castle, “Mind if I...?” She straightened up, untying the sash that was wrapped loosely around her middle, and shrugged out of her robe, the soft fabric falling in a gentle heap on the floor. “If he...?” Kate glanced at Castle, who’d rested back on his haunches, his erection rising proudly above the waistband of his jeans. She turned back to Serena. “No, go ahead. That is, if he wants...”

The eager grin on his face was the only answer either of them needed. 

“Condoms are in the paper bag on the floor next to you, Rick.” Serena pointed, then she tripped her fingers along Kate’s thigh again, pulling herself up the couch until their mouths met in a furious kiss, tongues and teeth and lips meeting, engaged in a lazy ballet. Kate could taste _herself_ on Serena’s roaming tongue, and she groaned, savoring the trippy experience of having _her_ flavors join with Serena’s.

“Got it,” Castle mumbled, standing up, toeing off his shoes, and quickly removing his jeans and boxers. He ripped open a foil packet, and then rolled the condom up the length of his thick shaft, taking care not to catch any hair beneath it. He glanced at Kate, who was leaning back against the sofa, one hand at her breast, teasing her nipple beneath the half-divested bra, the other stroking Serena’s hair as the other woman returned to her spot between Kate’s legs, only this time, instead of on her haunches, she was on all fours.

Completely nude. 

Waiting for Castle. 

He took off his jacket and unbuttoned his maroon colored shirt and then stood behind Serena, looking down at the blonde’s lithe body, her perfect alabaster skin. Kate watched his expression change from eager schoolboy to troubled lover. He glanced at her as though to say, ‘You sure this is okay?’ 

Kate nodded, feeling her climax build again. She opened her mouth as she closed her eyes and said, “Fuck her, Castle.”

He didn’t need to be told twice.  

 

* * *

 

**H** e got on his knees behind Serena and with one hand on her hip, used the other to guide himself to her entrance, teasing her, rubbing his tip against her wet folds, relishing the way she rocked her hips to chase him. She leaned back against him, shifting her pelvis up, eager, waiting, ready, wanting. He finally eased in, gasping as her muscles gripped him, accommodated him, contracted and pulsed around him.

He established a steady rhythm in and out, and in, and out, their bodies slapping together, using his hands to massage her tepid skin, skating one palm around to her front, squeezing her breast, his thumb and forefinger pinching her nipple. He glanced up at Kate and she was watching him, her face expressionless, her hazel-green eyes glassy and unfocused, her lips slightly parted, her hair gently framing her face, cascading around her shoulders, just licking the place above her nipples. Her breaths increased as Serena continued her Sapphic assault on Kate’s clit, her tongue rimming her soft inner folds, then returning to the hardened pearl, and he imagined shards of pleasure exploding from that spot. He’d seen it many times, that look, the way her body was coated in a thin sheen of sweat, her eyes faraway yet _there_ at the same time, he knew she was close.

Very close.  

For a panicked moment he was swept with doubt, not wanting anyone but _him_ to bring Kate that kind of pleasure, but then, as he watched her body seize up, her head tilt backwards, her breasts heave, her fingers dig into the couch cushions beneath her, she focused her gaze right _at_ him at the very moment the orgasm rippled through her, and his doubt was swept away with the tide of her climax. She had come with _him_ , even if it wasn’t _his_ tongue that had brought her there.

Serena rose up, still on her knees, and with Castle inside of her, reached behind to grab the back of his head, fisting his hair and pulling his mouth to hers, exploring its warm cavern with her tongue, her teeth.

She tasted like dark chocolate and white wine…and _Kate_. She tasted different than Beckett usually did, not bad, not necessarily good, either, just _different_. It was unusual, foreign, exciting but unnerving at the same time. She moaned in his mouth and then, with a final soft press of her lips to his, turned around to face Kate, who had removed her dress and bra, slipped out of her heels, and was on _her_ knees in front of Serena.

The two women kissed, Kate framing Selena’s face with both hands, her eyes closed, her fingers twining in Serena’s blond shoulder length tresses, and he could hear her panting, familiar, measured, he could smell her sweet breath and he closed his eyes and inhaled. Then he increased his pace, slamming into Serena, both hands bracketing her waist as he pounded in and out, her wetness coating his condom-covered cock, making it easy.

Serena’s whole body shuddered, and he realized that Kate had moved her hand to the place where they were joined, her fingers skating over him as he moved in and out, her thumb gliding over Serena’s clit. Kate grabbed a fistful of Serena’s hair, deepening their kiss, while Castle, feeling his climax building, established a punishing rhythm.

In, and out.

And, in.

And, out.

Over, and over until Serena was crying out, her strangled scream echoing off the walls of the hotel room. Kate watched, fascinated as the orgasm crashed through Serena, her body trembling, coated in sweat, her eyes screwed shut, her mouth open, her breaths quick, and Castle _knew_ the look on Kate’s face. She was hopped up, excited, intrigued, and he would place bets that it would take _nothing_ , just a feather touch, and Kate would be climaxing again, too.

Before Castle could orgasm himself, Serena told him to stop.

“Stop?”

“Yeah, I want...” she looked at Kate. “I want you both.”

Kate brushed the pads of her fingers against her lower lip, her eyebrows tugging together. “Wait. What?”

“I want you both inside of me.”

Castle stopped thrusting, exchanging puzzled glances with Kate. “How would that work, exactly?”

Serena chortled, “You’ve never heard of a strap-on?”

Castle grinned. “Ohhhh, heheh. Yeah, I, ah, yeah, I’ve heard of it.”

Serena moved forward, causing Castle to slip out of her and then pointed at a plastic bag beside the condoms. “In there,” she instructed Kate. She stood up. “Let’s move this party to the bed, shall we?” She ran a finger along Castle’s bicep as she passed him on her way to the bed, offering him a devilish smile.

A pair of French doors separated the massive king-sized bed from the rest of the suite, and Kate, dildo and strap-on in hand, and Castle, his _erection_ in hand, passed through them together, matching expressions of erotic curiosity on their faces.

Serena was waiting for them as she stood at the foot of the bed, and when they were within arms reach, she curled her hand around Castles neck, pulling him in for a deep kiss, her tongue exploring his mouth while her fingers roamed the broad expanse of his chest. Then she turned to Beckett, doing the same with her, an open mouthed kiss that he watched, unconsciously stroking himself, as the two women’s tongues darted out to meet and play, frolicking with each other with an easy half-familiarity.

This was beyond his wildest dreams. And, he’d has some pretty _wild_ fucking dreams!

When Serena was finished kissing Beckett, she turned to him, her eyes dropping to what his hand was doing and he stopped, his hand in mid-stroke.

“Castle, you need to lay on your back in the middle of the bed, and,” she turned to smile at Kate. “Kate, slip into that strap on for me, will you?” She padded to the side of the bed, opened a drawer and pulled out a bottle of cherry flavored lubricant. She waved it at him, “...we’ll need lots of this.”

Castle just stared at her, a blank look on his face until realization dawned and he opened his mouth. “Oh...Ohhhhh,” he chuckled. “Okay.” He’d naturally assumed that Serena would give him a blowjob while Kate fucked her with the dildo, but this, _this_ was even kinkier. He scrambled onto the bed, getting comfortable and then watched, fascinated, as Serena helped Kate into the dildo.

Kate turned to look at him, one eyebrow playfully arched, her hands on her hips as the purple dildo jutted out from between her legs. “Wadda say, Castle?” She teased, one eyebrow arched. “You want me to _fuck_ you?”

He felt his mouth go dry and his eyes grow huge. “No, no, ah, no thank you. I don’t think...I mean, I’m willing to try anything you know, but, I’m not sure...”

Serena laughed, “Don’t be a baby, Rick.” She climbed onto the bed on all fours and he watched as she crawled towards him. “You never know what you might like.” She opened the bottle of lubricant, squirting a generous amount into the palm of her hand, and then stroked his cock until it was covered with the slippery gel. Kate stood at the foot of the bed, watching, her eyes smoldering, one hand unconsciously stroking the dildo. Serena capped the bottle and tossed it to Kate. Eying the life-sized dildo and instructing, “Your turn,” before wiping her hand on a plush white hotel towel.

Kate quickly had the dildo lubed up and was wiping _her_ hands on the towel when Serena swung one leg over Castle’s middle, her back to him. She turned her head to look at him. “You ready?”

He nodded eagerly, his eyes like saucers, his head resting on a plush goose-down pillow.

“You’ll need to guide yourself in, Rick,” she instructed. “And, go _slowly_.” She gradually lowered herself over his stiff erection, and curling his fingers around his shaft, he teased his tip around her anus, enjoying the gasp that tumbled past her lips when he finally slipped the tip of his cock inside of her. She lowered herself around him slowly, _excruciatingly_ slowly, and it was a tight fit, which only made it _more_ pleasurable for him. When he was fully inside of her, she laid back, bringing her legs around to her front, bending her knees, her feet planted on the bed as her back made contact with his chest. She lolled her head on his collarbone as he slowly shifted his pelvis, forcing himself infinitesimally in and out of her.

“Ohhhhhh, fuuuuuuck,” she moaned. “Fuck, that feels amayyyyyzing.” He reached around and squeezed both of her breasts, his thumbs circling her hardened nipples, and then he glanced at Kate, who was watching the pair intensely, her eyes hooded, her lips parted.

She was still holding the rubber dildo in her hand, as though it were a new appendage with which she was trying to familiarize herself and it aroused Castle to no end seeing her like that.

Serena lifted her head and whispered, her voice low and gravely, “Kate. Come.”

She didn’t need to be told twice.

 

* * *

 

**S** he wasn’t jealous. She didn’t know why, either. Any normal woman would be enraged at the sight of her lover fucking another woman. But seeing Castle with Serena, especially when the other woman’s tongue had been tracing her clit, bringing Kate to such a delicious orgasm, she was void of any green-eyed emotion. She just wanted _in_.

Which is exactly what she was getting.

Kate crawled onto the bed, her eyes locked with Serena’s as she approached, and she ran her hands up the woman’s body, over the slope of her abdomen, the ladder of her ribcage, her palms filled by naturally endowed tear-shaped breasts and gumdrop nipples. She leaned in and took one nipple into her mouth, immediately rewarded by its rise and stiffening.

Serena moaned, staring at Kate through half-lidded eyes. “ _Fuck_ _me_ , Detective,” she whispered.

Kate smiled, positioning herself so she could enter Serena with the purple strap-on dildo. She knelt on one knee, her other foot resting by Serena’s hip, and then, as she watched Castle’s cock slide in and out of Serena’s ass, she eased the dildo in, filling her completely.

Serena took a sharp breath, clutching at the sheets, her eyes squeezed closed, her mouth open, her breaths short and quick and a thin sheen of sweat covered her entire body. For a brief moment, Kate was afraid she was hurting her, but then Serena moaned, opening her glassy eyes to look at Kate and smile. “Harder, Kate. Faster.”

Kate’s gaze shifted to Castle who was watching her with a lopsided grin on his face. They exchanged a knowing, seductive, hungry glance and then Kate slid the dildo almost completely out, and then slammed back in, causing Serena to cry out, a string of incomprehensible words spilling from her lips.

Kate fucked her, pumping in and out with a punishing rhythm, sometimes in time to Castle’s thrusts, other times in competition with them. She enjoyed watching their bodies, all three of their bodies, smashed together in a jumble of arms and legs and naked _fucking_ parts, pink and humming, vibrating, _tuned_ _in_ to one another. Kate and Castle took turns massaging Serena’s breasts, pinching her nipples, Kate bending down to sooth them with her tongue and lips, nip at them with her teeth as Castle ran his fingers in her long chestnut hair, palming her cheek. Kate took his finger into her mouth, sucking it, rolling it around her tongue, her hooded eyes capturing his as though making a promise, a sacred vow.

It didn’t take long before, without the usual buildup, Serena was _crashing_ around the unyielding dildo, the orgasm seizing her violently. She visibly trembled as wave after wave of pleasure washed over her satiated body until she was motionless and limp, her only movement being the rapid rise and fall of her chest as she panted for breath while lying between the detective and the writer.

Kate slowly pulled out of her, her lips caressing Serena’s swollen nipples, and then held out one hand to help Serena sit up as Castle eased out of her too. Serena rolled onto the mattress and scooted up the bed, laying beside Castle, one hand draped over her forehead, the other laying limply at her abdomen. She smiled slyly at Castle and then Kate. “You two make a great team,” she held up one finger. “I knew that the minute I met you last year, you two were a great team, but _this_ ,” she wagged her finger. “...this was _amazing._ ”

“It would be even more amazing if...” Castle’s eyes darted to his now _painful_ erection, having been the only one in the room to not achieve sweet release.

Serena giggled and Kate slipped out of the dildo, dropping it to the floor as she crawled beside him.  “Poor baby,” Kate purred, her fingers tracing lazy circles in the curly tufts of hair on his chest.

Serena sat up, reaching for him. “Well, we need to remedy that right now, don’t we?” She carefully rolled the condom off of him and then swung her legs out of the bed, strolling, naked, to the bathroom. “I’ll be right back.” She held up a warning finger to Kate. “Don’t let him _come_ without me.”

Kate smiled, coiling her body around him, using her fingers to tilt his head towards her as they kissed.  He tasted familiar, yet different somehow, remnants of _her_ still on his breath. His tongue plunged into the warm cavern of her mouth and she sucked it, her fingers raking through his tousled hair, leaving parallel lines in their wake. She felt a familiar tingle low in her belly and she ground her pelvis against his thigh, seeking relief. He tried to break away, but she trapped his bottom lip between the dangerous ridges of her teeth, eventually letting go with an audible _pop_.

He rubbed his bottom lip. “Nuh uh, Beckett. Not until _I_ get _mine_.”

“ _That_ shouldn’t be difficult to arrange,” Serena interjected, strolling back into the room after finishing in the bathroom. She’d disposed of the condom, peed, washed her hands, and was ready for more play. She crawled onto the bed, reclining on the other side of Castle, her head propped up in one hand. She waggled her eyebrows at Kate, and, as though telepathically transmitting her plan, both women sat up and scooted down the bed, hovering over Castle’s _impressive_ erection.

Serena held its base as Kate wrapped her lips around his tip, her tongue swirling it before running down his shaft. Serena joined her, their tongues leaving a wet trail up and down his cock, occasionally pausing to kiss each other before one or the other of them would take him completely in their mouth, pumping in and out, sucking and licking, then releasing him for the other to take.

Until finally he came, his deep baritone echoing from the high ceiling as Kate took all of him, her lips coaxing his orgasm as she sucked and swallowed, savoring his familiar flavor. Serena licked a trail of wayward cum that was spilling down his shaft before seizing Kate’s mouth in a lurid post-coital kiss.

When he was empty, softening, both women crawled up his body, nestling beneath each arm, Kate to his left, Serena to his right, and without a word, the trio drifted off to sleep, their carnal exploits having thoroughly exhausted them.

Especially, Castle.

Half an hour later, the sun having long ago set, Kate tiptoed into the bathroom and peered into the mirror, her body was still flushed and she had scratch marks everywhere. She narrowed her eyes and peered at her neck. A hickey. Fuck. She’d have to wear a turtleneck or scarf for the next week before that finally faded. She would have been pissed, except she couldn’t remember who’d given it to her. Castle, or Serena. She smiled at her reflection. She wasn’t sure she’d ever be up for doing this again, but god damned was she glad she’d done it at least this once.

Just thinking about it was making her aroused again. But, it was time to go. They had an early morning tomorrow.

When she sauntered back into the bedroom, Serena was already in her bathrobe, and Castle was half-dressed, sliding his arm into the sleeve of his shirt. Serena handed Kate her half-drunk glass of wine, and she took a sip, not at all embarrassed that she was now the only naked person in the room. She spied her bra and dress, now neatly laid over the couch cushion, and moved to go put them on.

But, not before stopping to thank Serena one last time. Her lips pressed against the art thief’s in a leisurely kiss. They parted and Kate grinned, whispering, “Thank you.”

Serena nodded, grinning like a Cheshire cat, glancing at Castle before returning Kate’s gaze. “Thank _you_.”

 

* * *

 

**I** n the elevator, fully dressed except for her underwear, which she’d been unable to find, Kate waited for the doors to close before she spun on Castle, a hungry grin on her face. “Holy shit, Castle. Can you believe we just did that?”

His eyes sparkling, flecks of gold dancing amid the baby blue, he grinned, growling. “I know, right?” He reached for her waist. “You,” he started, his lips at her ear, his tongue tracing its shell. “were amazing, Beckett. Hot. Hotter than hot. The hottest...”

She seized his mouth, her tongue curious and probing, her teeth trapping his lower lip, and then, remembering she should _breathe_ , parted and gasped for air. She backed him up against the elevator wall and ground her pelvis against him, a wicked grin gracing her face as she felt him grow hard.

He reached for the elevator panel and pushed the “stop” button, gathering her in his arms, spinning them and slamming her against the wall of the elevator, a whispered “unff” forced from her lungs.

“Ooh, sorry, you okay?”

“Shut up and fuck me, Castle.” Kate ordered.

He unzipped and was inside of her, thrusting quickly in and out as she wrapped her legs around his middle, her dress hiked up to her waist. She panted in his ear, whispering secrets and stories, chanting his name like it was a prayer, a litany, a talisman against the darker forces that sometimes tried to end them. He repeated _her_ name for the same reasons, “Kate, Kate, Kate. I love you, Kate.” In time to his thrusting hips.

They came simultaneously, unplanned, unspoken, calling out together in equal pleasure, equal rhythm, like one body, one orgasm, one pleasure. Bodies trembling, humming, _soaring_ together.

When they were done, he eased out of her and she let her feet drop to the floor, holding on to him to make sure her legs would keep her upright. She was overcome with it, the swell of emotion roaring through her, and she felt her eyes grow misty, her voice trembled as she spoke, “Castle.” She clutched at the lapel of his jacket, pressing her cheek against his chest, the odd scent of Serena and _her_ and _him_ clinging to his clothes. “Castle, I love you, too.”

They kissed, tongues and lips meeting for more than just the act of kissing, and this time, it was only _his_ flavor she could taste.

“Oooh,” he jumped. “I just remembered.” He reached into his jacket pocket and pulled out her panties. “Here.” He handed them to her.

She slipped into them, giving him a quizzical look. “Why? What?” She shook her head. “Nevermind.”

He pulled the “stop” button and the elevator lurched, resuming its plunge down to the lobby level. He entwined his fingers with hers. “Hungry?”

“Starving.”

He paused, watching the lights as they indicated their descent.

“For food, right?”

She snorted. “Yes, Castle. For food.”

**The End**

* * *

 

**A/N:** _This is pretty far outside of what I usually write. For those of you who know my other work and are completely scandalized, I apologize. But, you can blame Kristy for sending me the Kink-meme and challenging me to write it. I hope, at least, it met with her approval._

_And, I hope it satisfied the prompt._

_I had fun with it. :-)_


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